Apr 17, 2026 · The meaning of SIR is a man entitled to be addressed as sir —used as a title before the given name of a knight or baronet and formerly sometimes before the given name of a priest.

SIR definition: a respectful or formal term of address used to a man. See examples of sir used in a sentence.

Sir is a formal honorific address in English for men, derived from Sire in the High Middle Ages. Both are derived from the old French " Sieur " (Lord), brought to England by the French-speaking Normans, …

Sir is used at the beginning of a formal letter to a man you do not know: Dear Sir

People sometimes say sir as a very formal and polite way of addressing a man whose name they do not know or a man of superior rank. For example, a shop assistant might address a male customer as sir.

1. a polite form of address (spoken or written) to a man. Excuse me, sir!; He started his letter `Dear Sirs, ...'.

There are 19 meanings listed in OED's entry for the noun sir, two of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.